﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp1
{
    class area
    {
        public void Sum(double a)
        {
            double result;
            result = a * a * 3.14;
            Console.WriteLine("圆的面积为：" + result);
        }
        public void Sum(double a, double b)
        {
            double result;
            result = a * b;
            Console.WriteLine("长方形的面积为：" + result);
        }
    }
}
